Abstract: In recent years, with the continuous development of intelligent driving technology, millimeter-wave radar has received extensive attention as the core component of the automotive safety control system. Time division multiplexing (TDM) multiple-input multiple-output (MIMO) frequency modulated continuous wave (FMCW) radar is widely used in automotive radars due to its advantages of low hardware cost and high angular resolution. While the TDM MIMO has above advantages, in practical applications, there are also problems such as velocity ambiguity and angle ambiguity in the detection of moving targets, leading to greater detection errors. These problems have certain safety hazards for autonomous driving scenarios. In order to improve the above-mentioned problems of TDM MIMO FMCW radar and reduce the detection error, a target parameter estimation method of FMCW MIMO radar in the case of doppler ambiguity was proposed, which could ensure that the algorithm can improve the timeliness of monitoring with the condition of low complexity and solve the problems of velocity ambiguity and phase offset without additional hardware condition. The Kaiser window FFT beamforming method was used to measure the target angle to obtain more accurate target information. Simulation and experimental results verify the effectiveness of the proposed algorithm.